Fatal trap 12: page fault on Acer Chromebook 720 (peppy)

[Konstantin Belousov]

On Tue, Aug 21, 2018 at 12:14:35AM +0200, Michael Gmelin wrote:
> 
> 
> > On 20. Aug 2018, at 17:09, Konstantin Belousov <kostikbel at gmail.com> wrote:
> > 
> >> On Mon, Aug 20, 2018 at 12:45:12AM +0200, Michael Gmelin wrote:
> >> 
> >> See here for a screenshot (also including the output of "show pte
> >> 0xfffff80001000000"):
> >> 
> >> https://gist.github.com/grembo/78d0f2a100dd4f16775b85a118769658#file-ddb1-png
> > It is too early for ddb routines to register.
> > Ok can you try the following debugging patch, to verify my guess ?
> > 
> > diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
> > index 18777d23f09..cd05fdb763f 100644
> > --- a/sys/amd64/amd64/pmap.c
> > +++ b/sys/amd64/amd64/pmap.c
> > @@ -1052,8 +1052,7 @@ create_pagetables(vm_paddr_t *firstaddr)
> >        pd_p = (pd_entry_t *)DMPDkernphys;
> >        for (i = 0; i < (NPDEPG * nkdmpde); i++)
> >            pd_p[i] = (i << PDRSHIFT) | X86_PG_V | PG_PS | pg_g |
> > -                X86_PG_M | X86_PG_A | pg_nx |
> > -                bootaddr_rwx(i << PDRSHIFT);
> > +                X86_PG_M | X86_PG_A | pg_nx | X86_PG_RW;
> >        for (i = 0; i < nkdmpde; i++)
> >            pdp_p[i] = (DMPDkernphys + ptoa(i)) | X86_PG_RW |
> >                X86_PG_V;
> 
> With this change it boots okay (mptramp_pagetables is 0x1000000, as expected).

Can you apply the following on top of the previous debugging patch and show
me the line printed ?

diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
index 3d70532b7fd..613fa9f2165 100644
--- a/sys/amd64/amd64/pmap.c
+++ b/sys/amd64/amd64/pmap.c
@@ -2662,6 +2662,7 @@ pmap_pinit0(pmap_t pmap)
 		pmap->pm_pcids[i].pm_gen = 1;
 	}
 	pmap_activate_boot(pmap);
+printf("bootaddr addr %#lx rwx %#lx btext %#lx _end %#lx brwsection %#lx etext %#lx KERNBASE %#lx\n", 0x1000000UL, bootaddr_rwx(0x1000000UL), (uintptr_t)btext, (uintptr_t)_end, (uintptr_t)brwsection, (uintptr_t)etext, (uintptr_t)KERNBASE);
 }
 
 void